Correlation of DNA repair synthesis with ageing in mice, evidenced by quantitative autoradiography.

Fibroblasts from C57B1/6 female mice of different age have been treated with short-wave ultraviolet light. The amount of unscheduled DNA synthesis in the fibroblasts, determined by quantitative histoautoradiography, decreases with the donor's age. This result is discussed with regard to an increase in nuclear area and modifications of cell population dynamics with age. Moreover, differences between individuals of the same age group with regards to unscheduled DNA synthesis have been observed.